patch "usb: renesas_usbhs: fix usbhsf_fifo_clear() for RX direction" added to usb-linus

patch "usb: renesas_usbhs: fix usbhsf_fifo_clear() for RX direction" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    usb: renesas_usbhs: fix usbhsf_fifo_clear() for RX direction

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 0a2ce62b61f2c76d0213edf4e37aaf54a8ddf295 Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Wed, 27 Sep 2017 18:47:13 +0900
Subject: usb: renesas_usbhs: fix usbhsf_fifo_clear() for RX direction

This patch fixes an issue that the usbhsf_fifo_clear() is possible
to cause 10 msec delay if the pipe is RX direction and empty because
the FRDY bit will never be set to 1 in such case.

Fixes: e8d548d54968 ("usb: renesas_usbhs: fifo became independent from pipe.")
Cc: <stable@vger.kernel.org> # v3.1+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
---
 drivers/usb/renesas_usbhs/fifo.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index 03cac07f57b5..68f26904c316 100644
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -284,8 +284,17 @@ static void usbhsf_fifo_clear(struct usbhs_pipe *pipe,
 	struct usbhs_priv *priv = usbhs_pipe_to_priv(pipe);
 	int ret = 0;
 
-	if (!usbhs_pipe_is_dcp(pipe))
-		ret = usbhsf_fifo_barrier(priv, fifo);
+	if (!usbhs_pipe_is_dcp(pipe)) {
+		/*
+		 * This driver checks the pipe condition first to avoid -EBUSY
+		 * from usbhsf_fifo_barrier() with about 10 msec delay in
+		 * the interrupt handler if the pipe is RX direction and empty.
+		 */
+		if (usbhs_pipe_is_dir_in(pipe))
+			ret = usbhs_pipe_is_accessible(pipe);
+		if (!ret)
+			ret = usbhsf_fifo_barrier(priv, fifo);
+	}
 
 	/*
 	 * if non-DCP pipe, this driver should set BCLR when
-- 
2.14.1